Thermal methods and apparatus are known for studying chemical responses, such as phase changes or chemical reactions, by flowing a chemical substance through a conduit and measuring a temperature change caused by the response. For example, the conduit can be a covered channel in a plate, the channel being heated to a temperature at which a reaction will occur by a plurality of electrical resistance heaters positioned along the channel while a temperature change caused by a reaction is measured by a plurality of thermopiles which are also positioned along the channel (Zieren et al., American Institute of Chemical Engineers 2nd International Conference on Microreaction Technology (1998), Topical Conference Preprints, pages 154-163). Such systems represent an interesting advance in the art but such systems are relatively complex and expensive to manufacture.
The instant invention provides a solution to the above-mentioned problems. The instant invention is a thermal method for studying chemical responses, comprising the steps of: (a) flowing a chemical substance through a conduit, the conduit being in thermal communication with an electrical conductor, the electrical conductor being co-linear with the conduit, the electrical resistance of the electrical conductor being a function of the temperature of the electrical conductor; (b) flowing electricity through the electrical conductor during step (a); and (c) measuring the electrical resistance of the electrical conductor during step (b) to determine any change in the temperature of the conduit caused by a response of the chemical substance.
The instant invention is also an apparatus for studying chemical reactions, comprising: a first conduit, the first conduit being an electrical conductor, the first conduit having a first end and a second end, the electrical resistance of the first conduit being a function of the temperature of the first conduit; a source of electricity, the source of electricity in electrical communication with the first conduit so that electricity can be flowed through the first conduit; a volt meter in electrical communication with the first conduit so that the voltage measured by the volt meter is an indication of the temperature of the first conduit.